anechoic chamber

While a darkroom is a space that blocks out external light, an anechoic chamber is a space that blocks out external electromagnetic waves. An anechoic chamber not only prevents electromagnetic waves from entering from the outside, but also prevents internally generated waves from escaping, and its walls are made of materials that absorb electromagnetic waves rather than reflecting them. Anechoic chambers are used for testing the electromagnetic compatibility (EMC) of electrical and electronic devices, as well as for testing wireless equipment.